1. Field of the Invention
This invention relates to a navigation system and to a program for a navigation system setup method.
2. Description of the Related Art
In a conventional navigation apparatus the current location of the vehicle as detected by GPS (Global Positioning System), the angle of the vehicle which as detected by a gyro sensor, the direction of the vehicle, and a map of the vicinity of the current location are displayed on a map screen. Therefore, an operator, e.g., a driver, can run the vehicle in accordance with the current location and the direction of the vehicle which are displayed on the map screen.
Conventionally the driver can set a destination and, when the destination is set, a route from a place of departure or current location to the destination is searched by route search processing, and a route determined by the route search, i.e., the “searched route”, is displayed on a search route display screen. Accordingly, the driver can drive his/her vehicle along the searched route with guidance.
When expressways and toll roads connecting interchanges are included in the route from the place of departure to the destination determined by the route search processing, interchanges for entering the expressways and toll roads from open roads, i.e., entrance ramps, and exit interchanges, are searched in addition to the route. Next to the search route display screen is provided a setup screen showing interchanges for entering and exiting the toll roads and searched interchanges for getting on and off are displayed as defaults.
FIG. 2 shows one example of an interchange setup screen in a conventional navigation apparatus. Here an expressway is shown by way of example.
In the figure, AR1 is an area for indicating the interchange (IC) to get on, and AR2 is an area for indicating the interchange (IC) to get off, and AR3 is an area for indicating the searched interchange to get on or the searched interchange to get off, and hw1 to hw3 are expressways which connect to the interchanges indicated in the area AR3, and AR4 to AR6 are areas for indicating the interchanges of each expressway hw1 to hw3.
Adjacent to each area AR4 to AR6, keys k1 to k3 are displayed, and each time the keys k1 to k3 are depressed (or touched), the interchanges on each of expressways hw1 to hw3 are changed cyclically. For example, each time the key k1 is depressed, several interchanges short of the interchange displayed in the area AR3 in the direction of travel are cyclically displayed in the area AR4.
Firstly, the searched interchanges for getting on are displayed in the areas AR1 and AR3 as a default, and the searched interchange for getting off is displayed in the area AR2 as a default, and interchanges neighboring the interchange displayed in the area AR3 are displayed as defaults in the areas AR4 to AR6. An operator, e.g., a driver, selects a specific interchange by depressing one of the keys k1 to k3 and, subsequently, when the area in which the selected interchange was displayed is depressed (or touched), the selected interchange is designated as the interchange for getting on, and displayed in the area AR1.
Next, in the area AR3, as shown in the figure, the searched interchange for getting offs displayed as the default and, in the areas AR4 to AR6, the interchanges neighboring the interchange displayed in the area AR3 are displayed as defaults. The driver, by depressing one of the keys k1 to k3, selects a the specific interchange, and subsequently, when the area in which the selected interchange was displayed is depressed (or touched), the selected interchange is designated as the interchange for getting off, and displayed in the area AR2. In this manner, the interchanges for getting on and off are set and decided.
However, in the above-described conventional navigation apparatus, since the searched interchanges for getting on and off are displayed as defaults on the interchange setup screen, and the interchanges neighboring the interchanges for getting on and off are simply displayed as defaults, the driver can not see the entire route, and therefore it is difficult to recognize the relationship between positions of the place of departure and the destination and the interchanges for getting on and off and it is impossible to set appropriate interchanges for getting on and off according to the place of departure and the destination.